ACCUWEATHER: Heatwave to peak ahead of July 4th

Friday

Surging heat and humidity combined with light winds will create a dangerous heat wave in the northeastern United States, which is forecast to be at its peak this weekend into early next week.

However, even during and after Independence Day, hot and humid weather will roll on.

People who live for hot weather will be pleased, while some senior citizens, young children, folks with respiratory ailments and those who must do manual labor may be especially at risk.

How hot will it get?

Daytime temperatures will surge into the 90s F and AccuWeather RealFeel® Temperatures are projected to top 100 in the Northeast during the afternoon hours from Saturday through Monday.

Actual temperatures may even reach or exceed 100 degrees during the first two days of July.

While record temperatures are in the upper 90s to near 100 this time of the year, a few locations may still flirt with record highs, such as across New York state, Pennsylvania and New Jersey.

Neighborhoods will be abuzz with the sound of air conditioners and fans, while people will flock to area beaches, pools and water parks by the hundreds of thousands.

Remember to conserve electricity by turning off the fan or air conditioner when not at home or in the office.

"The only saving grace for those across eastern New England would be if cooler air can push in from the northeast to end the weekend," AccuWeather Senior Meteorologist Kristina Pydynowski said. "However, temperatures may be back off to the races by Tuesday even if this scenario pans out."

Why is this heat wave a concern?

Late June and early July are well within the realm of solar summer, which is the three months of the year with the highest sun angle. The summer solstice was on June 21.

People who plan on spending time outdoors, such as at the beach, pool or ballpark, should remember to use sunscreen.

People of all ages, regardless of their health and physical activity, indoors and out, will need to stay hydrated. Intake of alcoholic beverages should be limited, especially when there is no means to keep cool, such as in air conditioning.

Heat will build to dangerous levels in the urban areas of the major cities. The vast expanse of concrete, pavement and brick will give off heat through the night. Cooling stations, where people can escape from the heat for several hours, are warranted.

While late-model vehicles have much lower emissions than automobiles from back in the 1960s and 70s, air stagnation and poor air quality are a concern with this heat wave.

"Extended periods of sunny, hot, humid and calm weather are the perfect breeding ground for poor air quality conditions," according to AccuWeather Meteorologist Faith Eherts.

Ozone will be the main air quality threat, which peaks during the afternoon hours when sunlight is the strongest.

"The highest ozone concentrations are likely to be found in the vicinity of major highways, such as Interstate 95, and large metropolitan areas," Eherts said.

"Residents and visitors are encouraged to use public transportation, limit the use of grills, lawnmowers and other combustion engine power equipment and avoid prolonged periods of exertion outdoors."

Little to no rain in the offing

In terms of rainfall, most of the time through the Fourth of July will be free of rain.

Exceptions may be a shower or thunderstorm that affects parts of northern New York state and northern New England through Saturday. A few of these storms could turn heavy and gusty.

A few thunderstorms from the central Great Lakes can spread to the eastern Great Lakes and western slopes of the Appalachians on Monday, mainly in the afternoon.

Widely separated afternoon and evening storms may dot the region on Tuesday and Wednesday.

Heat may dominate into at least mid-July

The peak of the heat may occur Sunday into Monday, but temperatures are likely to remain at or above average through next week and into next weekend.

Temperatures are expected to be within a few degrees of 90 across the Northeast for the Fourth of July with even higher AccuWeather RealFeel® Temperatures. The exception will be in the mountains, where highs mostly in the 80s are expected.

"Last summer, the longest stretch of 90-degree days was mostly in the four- to five-day range for areas north of the Mason-Dixon Line," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said. "It looks like many places will surpass seven days with highs at or above 90 F into next week."

There may be a sneaky push of cool air from eastern Canada or the Atlantic Ocean that brings a break from the heat for a day or so. Most days, sea breezes will be limited to the beaches and a mile or so of the coast.

Pastelok sees signs of a turn to more seasonable weather with breaks in the heat for the second half of July.